Buttercoin
Buttercoin was a bitcoin exchange that spent time in private beta. While in beta, funding options described on TechCrunch reported that the startup had raised about $1.6 million, with backers including Y Combinator and Google Ventures, and had aimed at remittance-related local exchange rails.[1]
Closure
On 6 April 2015 TechCrunch reported Buttercoin was shutting down after failing to raise new investment, and quoted a company website notice:
"Buttercoin will be turning off our service on April 10th at 11PM Pacific. Be sure to move your bitcoins to another service and remove your dollar balances by Friday April 10th at 11PM."[1]
TechCrunch further quoted that unclaimed funds would be returned to the originating accounts, and characterised the wind-down as solvent — users to receive balances in full — attributing the exit to an inability to raise funding amid weaker Silicon Valley interest in bitcoin at the time.[1]